The present invention relates to bulk bed material carriers and particularly to such bulk beds utilizing an integral conveyor to assist in unloading material from the bulk bed.
There has been difficulty particularly in the farming industry to provide some form of bulk bed for receiving and efficiently discharging material in bulk quantity. Different crops have varying susceptibility to damage during handling. For example, potatoes must be handled very carefully to avoid bruising where other bulk materials such as sugar beets may be handled rather roughly since bruising does not affect the market for the crop. It is therefore desirable to obtain some form of material carrying and handling apparatus that will function to handle either crop as efficiently as possible. It is further desirable to obtain some form of bulk material holding and discharge apparatus that may be utilized for a variety of bulk materials other than farm produce.
Bulk beds have been designed to be attached to trucks in order to provide mobile support for bulk material. Such beds often include a horizontal conveyor that drags transverse bars along the length of the bed toward a discharge door. The material is engaged by the bars and forcibly moved toward the discharge end of the bulk bed. The problem arising with such cross members is that they become easily bound by dirt or rock particles that wedge between the bars and bulk bed, or that bind in the links of the chain attached to the transverse bars. Further, root crops such as potatoes are easily bruised when they are forced to slide across the bin floor.
Belt conveyors have a distinct advantage when being utilized to move material toward a discharge end of a bulk bed carrier. The conveyor belt will not drag the material along the bulk bed floor but, instead, acts as a support surface for the material and therefore prevents bruising while the material is delivered to the discharge end of the bed. However, there is considerable difficulty in providing a continuous belt conveyor that will move effectively under the relatively heavy loads provided by the bulk material carried thereon. The reason for this is that the end rolls that are normally used to drive the belt conveyor will slip against the underside of the belt since the roll and the belt surface are not positively engaged. This problem has been alleviated by producing bulk beds that include a false floor upwardly adjacent the working flight of the belt conveyor. This floor is selectively removable in sections when it is desired to remove the material of the bed to a different location. Sections of the false floor are removed to allow the material to drop onto the conveyor belt and be moved to the discharge end. However, it is very difficult to remove the false floor sections under the tremendous weight of the material within the bin.
U.S. Pat. No. 861,484 to Stewart granted July 30, 1907 discloses an endless carrier comprised of a chain having a number of plates carried thereon. The plates are mounted at forward or leading edges to the chain, with the trailing edges freely pivoted. The trailing edges overlap the leading edges of adjacent plates to form a substantially planar carrying belt or apron. The plates will drop to a vertical position on the lower or return run of the chain to prevent material from gathering on the inside of the conveyor belt surfaces. The chain is comprised of a series of interconnected links made from a single piece of wire or rod bent into a rectangular form. The forms are joined by integral eyelets at forward and rearward corners of the forms. The plates are fastened to transverse sections of the rod. Rollers or pulleys are utilized in place of sprockets to carry the chain and plates to define the conveyor working and return flights. The flaps are disclosed as being flexible or inflexible.
U.S. Pat. No. 1,322,032 to E. C. Litchfield et al granted Nov. 18, 1919, discloses a manure spreader. This spreader includes a hopper with walls converging downwardly toward the working flight of a conveyor that is comprised of a multiplicity of overlapped plates carried on an endless chain. The chain is driven by sprockets located at opposite longitudinal ends of the bin. One end of the bin includes a flexible covering that slides over the overlapped plates and allows discharge of manure therethrough.
Other patents of interest are U.S. Pat. Nos. 3,447,668; 3,901,377; 1,024,073; 1,388,407; and 3,265,188.